Tractor improvements



4, 1965 B. c. ARNOLD 3,202,016

TRACTOR IMPROVEMENTS Filed April 11, 1962 2 Sheets-Sheet 1 IN VEN TOR.

5,9005 6. A e/yaw Aug. 24, 1965 c. ARNOLD TRACTOR IMPROVEMENTS Filed April 11, 1962 2 Sheets-Sheet 2 INVENTOR. Bea/c5 C. ARNOLD W Arr'y United States Patent 3,202,016 TRACTOR IMPROVEMENTS Bruce C. Arnoid, Milan, lll., assignor to .i. 1. Case Com-- pany, Racine, Wis, a corporation of Wisconsin Filed Apr. 11, 1962, Ser. No. 186,740 6 Claims. (Cl. 74-7105) The present invention relates to differential locks, and

an object thereof is to generally improve the construction and operation of devices of this class.

In the use of tractors it sometimes happens that, when the ground is slippery in spots, better operation can be secured by eliminating the usual differential and operating in a manner as if the two traction wheels were connected by a single solid axle. This is true because the differential, neglecting losses, divides the engine torque equally between thetraction wheels. Torque can be developed, of course, only against resistance, and if one Wheel is momentarily on a slippery spot and has no traction, no torque can be applied to that wheel, and accordingly, by reason of the action of the differential, no torque can be applied to the other, and as a result no torque can be applied to either wheel, and no traction is possible. In other words, the tractor is helpless. However, if the traction wheels are tied together, the wheel momentarily having traction will receive torque, and if the load is not too great, the tractor may continue to operate, whereas, with the differential working, it cannot.

' Accordingly, it is a further object of the invention to provide a novel and useful differential lock for tractors.

A further object is to provide such a lock which will engage automatically at periods of minimum load, upon actuation of a suitable control, but which may be positively released if necessary by forceful actuation of the control. Further objects will be apparent from the following specification and accompanying drawing in which,

FIGURE 1 is a vertical, generally axial sectional view i of a typical differential embodying the invention;

FIG. 2 is an enlarged right side elevation of a clutch and shifting mechanism constituting the major portion of the differential lock; FIG. 3 is a sectional view on the line 3-4: of FIG. 2 enlarged;

FIG. 4 is a sectional view on the line 4-4 of FIG. 2 enlarged; and

FIG. 5 is a fragmentary front view of a control element on a scale comparable with FIGS. 3 and 4.

Similar reference characters have been applied to the same parts throughout the drawings and specification, which is to be taken as illustrative merely; the invention not being limited except as defined in the claims.

As seen in FIG. 1, the differential gear comprises primarily a shaft lit) on which is fixed a ring gear '12 so that it and shaft It) always rotate with each other, and at the same speed. Gear 12 is fixed on shaft iii by means of a pin 14 on which is journaled a differential pinion or gear 16, it being understood that more than one such pin and differential pinion are common and contemplated. Pinion 16 meshes with, and actuates gear portions 13 and 2% on sleeves 22 and 24, journaled on shaft Lit? and 3,ZZ,ill6 Patented Aug. 24, 1955 usual transmission housing of the tractor. Bushing 36 also carries an oil seal 40 of well-known type.

Sleeve 24 has splines 41 for some distance at its end remote from gear portion 20, and carries a brake element or disk 42 which is rotated by reason of rotation of sleeve 24 and its interlocking engagement with the splines 31 of sleeve 24. Brake element 42 is carried in a housing 44 fixed to bushing 36, the Whole being firmly united with transmision housing 38 by any suitable means, not shown, there being suitable braking means within housing 4-fnot shown, cooperating with disk 42. As so far described, the difierential is substantially conventional, and it will be understood that sleeve 22 is similarly supported in a bearing 46 carried in a bushing 48, a brake element 5%, rotating with sleeve 22 within a housing 52.

Shaft it extends beyond the outer end of sleeve 24 (right end in FIG. 1), and has splines 54 on which is slidably mounted a clutch element 55, which is therefore in effect slidably keyed to shaft 10. Clutch element 56 has internal teeth 58 complementary to the splines 41 on sleeve 24. Clutch element 56 is slidable on splines 54 and when it is shifted to the left into the dotted position in FIG. 1, teeth 58 engage splines 41 and therefore lock shaft lit) and sleeve 24 together for dependent or synchronous rotation. With clutch element 56 in this position, the differential is disabled for the following reason. Sleeve 24, of course, is locked to shaft it) and must rotate therewith at the same speed. Sleeve 22, however, although normallyfree to rotate in relation to shaft 19, cannot do so without rotating pinion 16 on pin 14. Pinion 26, however, cannot rotate without rotating sleeve 4 in relation to shaft it). But this is not possible in view of the lock-up between shaft 10 and sleeve 24 through clutch element 55, as explained, and sleeve 22 as well as sleeve 24 must rotate with shaft 19.

It will now be apparent that the differential may be disabled to give the effect of a solid axle or tie-up between the two traction wheels at any time, by merely shifting clutch element 55 to the left, as seen in FIG. 1; whereas differential action may be restored by shifting clutch element 55 to the right. Suitable mechanism is provided for accomplishing this, as willappear.

Brake housing 44 has an auxiliary chamber outwardly of the end of sleeve 24, enclosed by a cover plate 62. iournaled in bearings 64 and 66 FIG. 2, is a rockshaft 68 on which is journaled, in the present instance, a shipper generally designated as St Shipper St) has arms or fingers 82 and 84 carrying, by means of pins 86 and 88 shifter shoes 89 and 9-0 engaging a groove 91 in the above-mentioned clutch element 56. Rocking of shipper 8% for example from the full line to the dotted position in FIG. 1 and back, Will engage and disengage clutch element 56 with splines 41, and this is independent of any rocking of rockshaft 68.

Shipper is shifted by means of a spring 92, best shown in FIG. 3, connected to finger 82 by means of a connection 94 at the extremity of finger 82 remote from shaft 63, and to an anchorage generally designated as 96, comprising in the present instance a collar 98, FIG. 2, fixed on shaft 68 as by a pin 10f). Collar 98 has a plate or bracket 132 fixed thereto and providing a portion 104 spaced beyond the end of shaft 68 and having an opening in which spring 92 is secured. Rocking of shaft 68 will therefore carry the upper extremity of spring 92 to one side or the other of shaft 68, roughly in a direction parallel'to, or in the general direction of the axis of shaft 10. In FIG. 1, spring 92 has been carried to the right of shaft 68, exerting a pull on shipper 80 to the right. At such time as there is a momentary cessation of load between sleeve 24 and shaft 10, the pull of spring 92 will be sufficient to disengage clutch element 56, as

has occurred in FIG.

by Letters Patentof theYUnited-States is:

- This the parts.

is the normal position of In FIG. 3, spring 92 has been carried to the left and in like manner, has shifted clutch element 56 to the left into position-to lock sleeve 24 to shaft 10. The advantage of this type of operation is that, if there is a large difference in speed betweenshaft 10 and sleeve 24 such that engagement would cause a damaging shock, teeth 58 will ride the ends 'of the splines 41 and not'engage under ever, as soon as the speeds become somewhere near equal,

as will happen momentarily during operation, the resili-,

ent pressure of spring 92 will engage-the clutch and accomplish the disabling of the differential.

Turning now to FIG. 5, shaft 68 extends, in the present instance forwardly, outside of housing 60, andhas a control-lever or pedal 106, having a'portion 108 normally extending in front of brake housing 44. If the operator senses a need to disable the differential, he has rnerely to press portion 108, for example with his heel, fromthe dotted position in FIG. 5 to thefull line position, whereupon he will s'etthe parts in the relation shown ,in'FIGL -3 so that the tractor will operate as with'a solid axle.

ture. R The tension or torsion of spring'100-will tend to return lever 106 to the dotted position as soon as re- As stated, the tension of above-mentioned spring '9 will disengage clutch element 5 6-at suchtimes as the load on clutch element 56 is momentarily eliminated. Under some conditions this may'n'ot come about, and therefore positive means is provided, to disengage the clutch even under load. Referring to FIG; 4,;shaft 68 has fixed thereon, a cam member '114, as byineansof a pin 116, and which has a finger 118 arranged, in the position of the parts shown inFIG. 3, to contact aroller .or tappet portion 120 on -a .lever arm 122, in turn ful-' I crumed onra pin 1 24 fixed'in the wall of chamber 60 as by.

, a nut125, FIG.' 2. Lever122'ha's a roller'or'tappet 126 ,j

spaced from tappet 120 on the side of fulcruni'pin 1241 remote from roller 120. Roller 126 is in positionrto con tact a follower portion 128forrningla part of above-mentioned fineger 84. Movementcof finger 118 to the left by reason of clockwise rotation'of shaft 68 will rock lever 122 in a counterclockwise direction, causing roller per 80 in the proper direction to disengage clutch element 56. Therefore it is not necessary to depend 'upon 106' in the full line position through the-action of lever 122, a kick on lever 106 by the operator, forcing it, back to the dotted position, will actuate finger, 118 to posileased by the operator, ,so that the differential will go 'back into operation automatically.

- 126 to force finger 84 to the right, thus rocking ship'- *4 slidably keyed on said shaft beyond the end of the last mentioned sleeve, and shiftable axially of'said shaft into interlocking engagement with, the teeth on said last mentioned sleeve, for locking up the differential gear; and 1 cans connected with said clutch element for shift- 'ing it into and out of engagement with saidlastmen- -tio ned sleeve." 7 a v 2. In a control for use in a differential gear of the type having a pair of differentially. rotatable parts one of said parts comprising a shaft, and the other comprising a driving'sleeve the combinationof a f I V v clutch element shiftable axially of said shaft and engageable with said shaft and with said driving sleeve to lock said shaft and said driving sleeve together for preventing the] differential action, a 5 shipper engaged with said clutch element and movable in the direction of the axis of said shaft, a spring anchorage supported for shifting movement in the direction, of the axis of .said shaft, 6 means for shifting said spring anchorage in said direction,andaspring, stressed between said spring anchorage and said shipper in position totend to shift, by reason of its stress, said shipper in a direction opposite to that in i which said spring anchorageisshifted.

3. Ina control for use ma differential gear of the type spring anchorage supported'fonshifting movement in i the direction of the axis of said shaft, 7

means for shifting saidspr-ing anchorage in said directionra 1 spring', stressed between said spring anchorage and said shipper in position tote'nd to shift, byl reason of its stress, said shipper in a direction opposite to that' in which said spring anchorage is shifted and means interposed between saids'pring anchorage and said shipper, engageable with and movable by shifting 'of'saidspring anchorage in one direction, and by-reason of such movement, engagcable with and moving said shipper in the opposite direction; a 4; In a control for use'in a differential gear of the type having a pair of differentially rotatable parts, one ofsaid parts including a central shafathe combination of a tively shift shipper 80 through lever i122, and disengage clutch element 56 fromsleeve 24. Thus, while the, dif- I ferential lock will work. in a sense automatically, upon a signal from lever 106, it can be positively unlocked at anytime by' the exertion of force on lever 1 06,.

I The operation of the device is thought to' be clear, 1 from the foregoing, anditis apparent that the mechanism shown will' accomplish the objects of the invention, as hereinbefore stated. a

What is .claimedas new; and

desired to be secured,

" 1.'In a control for use ina'ditferential'gear of the type teeth on one of s'aid sleeves, a toothed'clutchelement housing, I a

clutchelernent in said housing,;shiftable axially of said I shaft and'en'gageable with-said. shaft and with theother rotatable part for locking said differentially rotatable parts together for preventing the differential action of said differential gear, a rockshaft journaled in said housing, transverse to, and spaced from said central shaft, a 7 V shipperjournaled on said rockshaft, and engaged with said clutch element for shifting it axially by reason of rocking of said, shipper, 7

means for rocking said r'ockshaft, a

bracket onsaid rockshaft, a a

spring having one end connected to said bracket in position to be shifted in the general direction of the length of saidcentral shaft'upon-rocking of said rockshaft, and stressed between said bracket and a portion on said shipper remote from saidfrockshaft, saidvbracket being so locatedithat rocking ofsaid rockshaft shifts :saidend of, said spring from one side to the other a of a line between said'rockshaftand said portion on saidshipper, whereby-rocking of said rockshaft will cause said spring to exert resilient shifting pressure central shaft and a clutch element shiftable axially of the shaft for locking said parts together for locking up the differential gear, the combination of a housing for said clutch element, a

rockshaft journaled in the housing transverse to and spaced from said central shaft, a

shipper journaled on the rockshaft and engaged in shifting relation with said clutch element, and means for rocking said shipper for shifting said clutch element including means for rocking said rocksha-f-t, a

bracket on said rockshaft, a

tension spring having one end connected to said shipper at a point remote from said rockshaft and the other end connected with said bracket at a point such that rocking of said rockshaft shifts the second mentioned end of said spring from one side to the other of a line between said rockshaft and said point Where said spring is connected to said shipper, whereby resilient pressure Will be exerted by said spring tending to rock said shipper by reason of rocking of said rockshaft, a

cam member on said rockshaft, a

lever journaled in said housing and extending from said cam member to a point adjacent said shipper spaced from said rockshaft,

means on said lever engaged by said cam member positioned to receive motion from said cam member by reason of rocking of said rockshaft in one direction, and

means on said lever positioned to engage said shipper at a point spaced from said rockshaft, upon motion of said lever imparted thereto by said cam means, to rock said shipper and shift said clutch element independently of said spring when said rocksh-aft is rocked in said one direction. 6. In a control for use in a differential gear of the type including a shaft, a ring gear fixed to a mid-portion of the shaft, a differential pinion journaled on said ring gear and a pair of driving sleeves journaled on said shaft, one at each side of said ring gear, driven from said differential pinion, said driving sleeves having splined portions outwardly of said differential pinion, and brake elements carried on said splined portions, the combination including a plurality of teeth on said splined port-ions, one of said splined portions extending beyond its respective brake element on the side opposite said differential pinion, a toothed clutch element slidably keyed on said shaft beyond the end of the last men-tioned splined portion, and shiftable axially of said shaft into interlocking engagement with the teeth :on said last mentioned splined portion beyond said brake element, for disabling the differential action of said differential gear, and

means connected with said clutch element for shifting it into and out of engagement with said last mentioned splined portion.

References Cited by the Examiner UNITED STATES PATENTS 1,540,247 6/25 Bowman.

2,306,545 12/42 Kummich 74710.5 X 2,450,364 6/49 Foster 192-89 2,832,233 4/58 Allgaier et al. 74-7105 X DON A. WAITE, Primary Examiner.

BROUGHTON G. DURHAM, Examiner. 

1. IN A CONTROL FOR USE IN A DIFFERENTIAL GEAR OF THE TYPES INCLUDING A SHAFT, A RING GEAR FIXED TO A MID-PORTION OF THE SHAFT, A DIFFERENTIAL PINION JOURNALED ON SAID RING GEAR AND A PAIR OF DRIVING SLEEVES JOURNALED ON SAID SHAFT, ONE AT EACH SIDE OF SAID RING GEAR, AND DRIVEN FROM SAID DIFFERENTIAL PINION, THE COMBINATION INCLUDING A PLURALITY OF TEETH ON ONE OF SAID SLEEVES, A TOOTHED CLUTCH ELEMENT SLIDABLY KEYED ON SAID SHAFT BEYOND THE END OF THE LAST MENTIONED SLEEVE, AND SHIFTABLE AXIALLY OF SAID SHAFT INTO INTERLOCKING ENGAGEMENT WITH THE TEETH ON SAID LAST MENTIONED SLEEVE, FOR LOCKING UP THE DIFFERENTIAL GEAR, AND MEANS CONNECTED WITH SAID CLUTCH ELEMENT FOR SHIFTING IT INTO AND OUT OF ENGAGEMENT WITH SAID LAST MENTIONED SLEEVE. 